[cprocess]

This is good information. Another benefit of using constant current is that it enables you to use the "Rule of 720" to calculate anodizing time to get a specific thickness. This rule states that it takes 720 amp minutes per square foot to produce one mil of oxide coating. In application, divide 720 by your current density (in amps per square foot). This will be the time required to produce 1 mil of oxide coating. For example, if I have 2 square feet of surface area to anodize, rectifier is set on 40 amps (= 20 amps per square foot), I divide 720 by 20 = 36 minutes to apply 1 mil of oxide coating.